A method of RF signal processing comprises receiving an incoming RF signal at each of a plurality of antenna elements that are arranged in a first pattern. The received RF signals from each of the plurality of antenna elements are modulated onto an optical carrier to generate a plurality of modulated signals that each have at least one sideband. The modulated signals are directed along a corresponding plurality of optical channels with outputs arranged in a second pattern corresponding to the first pattern. A composite optical signal is formed using light emanating from the outputs of the plurality of optical channels. Non-spatial information contained in at least one of the received RF signals is extracted from the composite signal.

A method of RF signal processing comprises receiving an incoming RF signal at each of a plurality of antenna elements that are arranged in a first pattern. The received RF signals from each of the plurality of antenna elements are modulated onto an optical carrier to generate a plurality of modulated signals that each have at least one sideband. The modulated signals are directed along a corresponding plurality of optical channels with outputs arranged in a second pattern corresponding to the first pattern. A composite optical signal is formed using light emanating from the outputs of the plurality of optical channels. Non-spatial information contained in at least one of the received RF signals is extracted from the composite signal.

A method and apparatus includes an optical source for a single order single-sideband suppressed-carrier optical signal with a bandwidth that scales from over 4 gigaHertz or is at least 8 GHz from an optical carrier frequency. In an example embodiment, an apparatus includes a stable laser source configured to output an optical carrier signal at a carrier frequency. The apparatus includes a radio frequency electrical source configured to output an electrical radio frequency signal with a radio frequency bandwidth less than one octave. The apparatus also includes an optical modulator configured to output an optical signal with the optical carrier signal modulated by the radio frequency signal in a plurality of orders (harmonics) of optical frequency sidebands. The apparatus further includes an optical filter configured to pass one single order optical frequency sideband of the optical signal, which sideband does not overlap the sideband of any other harmonic.

A method for operating an optical modulator includes receiving a narrowband radio frequency (“RF”) signal. The method further including, responsive to receiving the narrowband RF signal, modulating the narrowband RF signal using a double sideband suppressed carrier (“DSBSC”) modulation scheme to generate a DSBSC optical signal. The method further including transmitting the DSBSC optical signal to an optical transmitter.

A scheme for generating asymmetric single sideband photonic vector signal at millimeter wave spectral region is described. At a transmitter, information bits to be transmitted are modulated using a vector modulation technique to generate a baseband signal. The baseband signal is converted into its single sideband (SSB) version using a complex frequency source having a first frequency. The real part of the upconverted signal is added to the real part of a second frequency source and is input as I component to an I/Q modulator. The imaginary part of the upconverted signal is added to the imaginary part of the second frequency source and is used as the Q component. The I/Q modulator is driven by a laser source at frequency fc. The resulting signal is transmitter over an optical transmission medium and upconverted by a single-ended photodiode to a desired radio-frequency (RF) carrier frequency.

Length metrology apparatuses and methods are disclosed for measuring both specular and non-specular surfaces with high accuracy and precision, and with suppressed phase induced distance errors. In one embodiment, a system includes a laser source exhibiting a first and second laser outputs with optical frequencies that are modulated linearly over large frequency ranges. The system further includes calibration and signal processing portions configured to determine a calibrated distance to at least one sample.

Provided is an optical communication system capable of suppressing the deterioration of an intensity waveform of an optical intensity modulated signal subjected to transformation using SSB modulation and improving a bit error ratio and a receiver sensitivity of the optical intensity modulated signal. The optical communication system includes: an optical transmitter section including: a single-side band modulation circuit configured to subject a double-side band modulated signal to generate a single-side band modulated signal; a correction circuit configured to correct an intensity of the single-side band modulated signal so that the intensity of the single-side band modulated signal becomes closer to an intensity of the double-side band modulated signal; and an optical IQ modulator configured to output an optical modulated signal; and an optical receiver section configured to receive the optical modulated signal to directly detect an intensity component of the optical modulated signal.

An optical frequency shifter includes a splitter that branch a first optical signal having a first frequency component, a first mutual phase modulator that generate a second optical signal having a second frequency component and a third optical signal having a third frequency component with mutual phase modulation of the first optical signal and a first optical beat signal, a phase converter that change a phase of an output of the first mutual phase modulator, a second mutual phase modulator that generate the second optical signal and the third optical signal with mutual phase modulation of the first phase converter of output signal and a second optical beat signal, and a combiner that interfere between an output of the second mutual phase modulator and another optical signal obtained by branching of the splitter.

A method for creating an optical transmit signal includes creating an electrical discrete multi-tone signal according to digital input data carrying the information to be transmitted, the discrete multi-tone signal having a plurality of electrical partial signals, each electrical partial signal defining a sub-channel. Each electrical partial signal includes a sub-carrier at a predetermined sub-carrier frequency which is modulated according to a dedicated modulation scheme, so that a dedicated portion of the digital input data is included in each sub-channel. The method includes creating an optical signal by using the electrical discrete multi-tone signal as modulating signal for amplitude-modulating the intensity of an optical carrier signal. The method further includes bandpass-filtering the optical signal in order to create an optical single sideband or vestigial sideband transmit signal. An optical transmitter device for creating such an optical transmit signal and to an optical transmitter and receiver device includes a respective optical transmitter device.

Disclosed herein are system, method, and computer program product embodiments for synchronizing the switching of different wireless platforms to different portions of a frequency band. An embodiment, at a first wireless platform, operates by receiving a band switch request message from a second wireless platform, wherein the band switch request message comprises a band switch delay period for the second wireless platform. The embodiment calculates a band switch time based on a band switch delay period for the first wireless platform and the band switch delay period for the second wireless platform. The embodiment transmits a band switch accept message comprising the band switch time to the second wireless platform. The embodiment sets a first filter to operate on a second portion of the frequency band based on the band switch time. The embodiment then operates on the second portion of the frequency band.